U.S. patent application number 16/552756 was filed with the patent office on 2019-12-19 for ultra-wideband radio frequency tracking for determining and controlling positioning error of an implement on a work vehicle.
The applicant listed for this patent is Deere & Company. Invention is credited to Mark J. Cherney, Michael G. Kean.
Application Number | 20190387360 16/552756 |
Document ID | / |
Family ID | 62716441 |
Filed Date | 2019-12-19 |
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United States Patent
Application |
20190387360 |
Kind Code |
A1 |
Kean; Michael G. ; et
al. |
December 19, 2019 |
ULTRA-WIDEBAND RADIO FREQUENCY TRACKING FOR DETERMINING AND
CONTROLLING POSITIONING ERROR OF AN IMPLEMENT ON A WORK VEHICLE
Abstract
A method and system of position determination of an implement on
a work vehicle. The method includes determining a position of a
first radio frequency (RF) device relative to a local reference
frame using ultra-wideband ranging between the first RF device and
at least one additional RF device. The first RF device is coupled
to a fixed location on the implement, and the additional RF device
is mounted at a fixed location relative to the local reference
frame. The implement is controllably movable relative to the local
reference frame. A position and orientated of the implement is
determined relative to the local reference frame based at least in
part on the determined position of the first RF device relative to
the local reference frame.
Inventors: |
Kean; Michael G.; (Dubuque,
IA) ; Cherney; Mark J.; (Dubuque, IA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Deere & Company |
Moline |
IL |
US |
|
|
Family ID: |
62716441 |
Appl. No.: |
16/552756 |
Filed: |
August 27, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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15410309 |
Jan 19, 2017 |
10469988 |
|
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16552756 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W 4/026 20130101;
H04W 4/023 20130101; H04W 4/44 20180201; H04M 2250/10 20130101;
H04W 4/029 20180201 |
International
Class: |
H04W 4/02 20060101
H04W004/02 |
Claims
1. A positioning system for a work vehicle with an implement, the
positioning system comprising: a first radio frequency (RF) device
mounted at a fixed location relative to the implement; at least one
additional RF device mounted at a fixed location relative to a
local reference frame; and an electronic controller configured to
determine a position of the first RF device relative to the local
reference frame using ultra-wideband ranging between the first RF
device and the at least one additional RF device, determine a
position of the local reference frame relative to a global
coordinate system, determine a position and orientation of the
implement relative to a global coordinate system based at least in
part on the determined position of the first RF device relative to
the local reference frame and the determined position of the local
reference frame relative to the global coordinate system, wherein
the implement is controllably movable relative to the local
reference frame, and perform at least one function based on a
comparison between the determined position of the implement
relative to the global coordinate system and a target position of
the implement relative to the global coordinate system.
2. The positioning system of claim 1, wherein the electronic
controller is further configured to determine a positioning error
based on a difference between the determined position of the
implement relative to the global coordinate system and the target
position of the implement relative to the global coordinate
system.
3. The positioning system of claim 2, wherein the electronic
controller is configured to perform the at least one function based
on the comparison by transmitting a signal to an indicator in
response to determining the positioning error, wherein the
indicator is configured to provide an indication of the positioning
error to an operator of the work vehicle in response to receiving
the transmitted signal from the electronic controller.
4. The positioning system of claim 2, wherein the electronic
controller is further configured to determine the target position
of the implement relative to the global coordinate system by
accessing a work plan stored to a memory, and wherein the
electronic controller is configured to perform the at least one
function based on the comparison by recording deviations from the
work plan based on the determined positioning error.
5. The positioning system of claim 1, wherein the work vehicle
includes one or more actuators configured to adjust the position
and the orientation of the implement in response to one or more
control signals from the electronic controller, and wherein the
electronic controller is configured to perform the at least one
function based on the comparison by adjusting the position and the
orientation of the implement, by transmitting the one or more
control signals to the one or more actuators, to reduce a
difference between the determined position of the implement
relative to the global coordinate system and the target position of
the implement relative to the global coordinate system.
6. The positioning system of claim 1, wherein the work vehicle is a
motor grader and the implement is a motor grader blade, wherein the
motor grader includes one or more actuators configured to adjust
the position and the orientation of the motor grader blade relative
to a main body of the motor grader in response to control signals
received from the electronic controller, wherein the electronic
controller is further configured to determine a plurality of target
positions for the motor grader blade in the global coordinate
system at different locations on the work site surface based on an
accessed work site plan, and wherein the electronic controller is
configured to perform the at least one function based on the
comparison by transmitting one or more control signals to the one
or more actuators to controllably adjust the position and the
orientation of the motor grader blade as the motor grader moves
across the work site surface to cause the determined position of
the motor grader blade to approach the target position of the motor
grader blade at each of the different locations on the work site
surface.
7. The positioning system of claim 1, wherein the at least one
additional RF device is mounted to a fixed location relative to a
main body of the work vehicle, wherein the local reference frame is
fixed relative to the main body of the work vehicle, wherein the
electronic controller is configured to determine the position and
the orientation of the implement relative to the local reference
frame by determining the position and the orientation of the
implement relative to the main body of the work vehicle, and
wherein the electronic controller is configured to determine the
position of the local reference frame relative to the global
coordinate system by determining the position of the main body of
the work vehicle relative to the global coordinate system.
8. The positioning system of claim 7, wherein a power amplitude of
the ultra-wideband ranging is configured to provide a tracking
range that is less than a length of the work vehicle, and wherein
the ultra-wideband ranging is configured such that a decrease in
the tracking range results in a corresponding increase in a
tracking accuracy.
9. The positioning system of claim 1, wherein the at least one
additional RF device is mounted to a fixed location relative to a
work site on which the work vehicle is operating, wherein the local
reference frame is fixed relative to the work site, wherein the
main body of the work vehicle is controllably movable relative to
the local reference frame, wherein the electronic controller is
configured to determine the position and the orientation of the
implement relative to the local reference frame by determining the
position and the orientation of the implement relative to the work
site, and wherein the electronic controller is configured to
determine the position of the local reference frame relative to the
global coordinate system by determining the position of the work
site relative to the global coordinate system.
10. The positioning system of claim 9, wherein a power amplitude of
the ultra-wideband ranging is configured to provide a tracking
range that is less than a length of the work site, and wherein the
ultra-wideband ranging is configured such that a decrease in the
tracking range results in a corresponding increase in a tracking
accuracy.
11. A method of position determination of an implement on a work
vehicle, the method comprising: determining a position of a first
radio frequency (RF) device relative to a local reference frame
using ultra-wideband ranging between the first RF device and the at
least one additional RF device, wherein the first RF device is
mounted at a fixed location relative to the implement, and wherein
the at least one additional RF device is mounted at a fixed
location relative to the local reference frame; determining a
position of the local reference frame relative to a global
coordinate system; determining a position and orientation of the
implement relative to a global coordinate system based at least in
part on the determined position of the first RF device relative to
the local reference frame and the determined position of the local
reference frame relative to the global coordinate system, wherein
the implement is controllably movable relative to the local
reference frame; and automatically performing at least one function
based on a comparison between the determined position of the
implement relative to the global coordinate system and a target
position of the implement relative to the global coordinate
system.
12. The method of claim 11, further comprising determining a
positioning error based on a difference between the determined
position of the implement relative to the global coordinate system
and the target position of the implement relative to the global
coordinate system.
13. The method of claim 12, wherein performing the at least one
function based on the comparison includes transmitting a signal
from an electronic controller to an indicator in response to
determining the positioning error, wherein the indicator is
configured to provide an indication of the positioning error to an
operator of the work vehicle in response to receiving the
transmitted signal from the electronic controller.
14. The method of claim 12, further comprising determining the
target position of the implement relative to the global coordinate
system by accessing a work plan stored to a memory, and wherein
performing the at least one function based on the comparison
includes recording deviations from the work plan based on the
determined positioning error.
15. The method of claim 11, wherein the work vehicle includes one
or more actuators configured to adjust the position and the
orientation of the implement in response to one or more control
signals from an electronic controller, and wherein performing the
at least one function based on the comparison includes adjusting
the position and the orientation of the implement, by transmitting
the one or more control signals from the electronic controller to
the one or more actuators, to reduce a difference between the
determined position of the implement relative to the global
coordinate system and the target position of the implement relative
to the global coordinate system.
16. The method of claim 11, wherein the work vehicle is a motor
grader and the implement is a motor grader blade, wherein the motor
grader includes one or more actuators configured to adjust the
position and the orientation of the motor grader blade relative to
a main body of the motor grader in response to control signals
received from an electronic controller, the method further
comprising determining a plurality of target positions for the
motor grader blade in the global coordinate system at different
locations on the work site surface based on an accessed work site
plan, and wherein performing the at least one function based on the
comparison includes transmitting one or more control signals from
the electronic controller to the one or more actuators to
controllably adjust the position and the orientation of the motor
grader blade as the motor grader moves across the work site surface
to cause the determined position of the motor grader blade to
approach the target position of the motor grader blade at each of
the different locations on the work site surface.
17. The method of claim 11, wherein the at least one additional RF
device is mounted to a fixed location relative to a main body of
the work vehicle, wherein the local reference frame is fixed
relative to the main body of the work vehicle, wherein determining
the position and the orientation of the implement relative to the
local reference frame includes determining the position and the
orientation of the implement relative to the main body of the work
vehicle, and wherein determining the position of the local
reference frame relative to the global coordinate system includes
determining the position of the main body of the work vehicle
relative to the global coordinate system.
18. The method of claim 17, wherein a power amplitude of the
ultra-wideband ranging is configured to provide a tracking range
that is less than a length of the work vehicle, and wherein the
ultra-wideband ranging is configured such that a decrease in the
tracking range results in a corresponding increase in a tracking
accuracy.
19. The method of claim 11, wherein the at least one additional RF
device is mounted to a fixed location relative to a work site on
which the work vehicle is operating, wherein the local reference
frame is fixed relative to the work site, wherein the main body of
the work vehicle is controllably movable relative to the local
reference frame, wherein determining the position and the
orientation of the implement relative to the local reference frame
includes determining the position and the orientation of the
implement relative to the work site, and wherein determining the
position of the local reference frame relative to the global
coordinate system includes determining the position of the work
site relative to the global coordinate system.
20. The method of claim 19, wherein a power amplitude of the
ultra-wideband ranging is configured to provide a tracking range
that is less than a length of the work site, and wherein the
ultra-wideband ranging is configured such that a decrease in the
tracking range results in a corresponding increase in a tracking
accuracy.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/410,309, filed Jan. 19, 2017, entitled
"ULTRA-WIDEBAND RADIO FREQUENCY TRACKING OF AN IMPLEMENT ON A WORK
VEHICLE," the entire contents of which are incorporated herein by
reference.
BACKGROUND
[0002] Some work vehicles may be equipped with position sensors
that detect a change in position of an implement of the work
vehicle along a given direction. For example, a work vehicle may be
equipped with rotation sensors or cylinder position sensors that
detect positional changes of implements on the work vehicle (for
example, a blade on a road grader or a boom on an excavator).
However, position sensors may have limited precision in sensing
position due to hysteresis in gearing or linkage that control the
movement of the implement.
[0003] Another method of position determination of an implement on
a work vehicle is attaching a global positioning system (GPS)
receiver to the implement. For example, a road grader may include
one or more masts extending from the blade that have a GPS receiver
installed thereon. The GPS receiver provides the work vehicle with
an approximate location of the mast. However, using GPS technology
provides only rough approximation of the position of the implement
and the size and position of the masts can restrict movement,
usage, and design of the implement.
SUMMARY
[0004] Some embodiments described herein provide systems and
methods for position determination of an implement on a work
vehicle with respect to a local reference frame using
ultra-wideband ranging. The system may incorporate GPS to define
the local reference frame with respect to a global reference frame.
The system provides a mastless solution that provides high accuracy
position detection. In particular, the system may track the
position of the implement with accuracy approaching 2 mm. By
establishing the local reference frame with high accuracy position
detection, the system provides increased precision of position
control of the implement on the work vehicle.
[0005] One embodiment provides a method of position determination
of an implement on a work vehicle. The method includes determining
a position of a first radio frequency (RF) device relative to a
local reference frame using ultra-wideband ranging between the
first RF device and at least one additional RF device. The
additional RF device is mounted at a fixed location relative to the
local reference frame, and the first RF device is coupled to a
fixed location on the implement. The implement is controllably
movable relative to the local reference frame. The method includes
determining a position and an orientation of the implement relative
to the local reference frame based at least in part on the
determined position of the first RF device relative to the local
reference frame.
[0006] Another embodiment provides a system for determining a
position of an implement on a work vehicle. The system includes a
first radio frequency (RF) device coupled to a fixed location on
the implement and at least one additional RF device mounted at a
fixed location relative to a local reference frame. The system also
includes an electronic processor communicatively coupled to the
first RF device and the at least one additional RF device. The
electronic processor is configured to determine a position of the
first RF device relative to the local reference frame using
ultra-wideband ranging between the first RF device and the at least
one additional RF device. The electronic control unit determines a
position and an orientation of the implement relative to the local
reference frame based at least in part on the determined position
of the first RF device relative to the local reference frame.
[0007] Other aspects of the disclosure will become apparent by
consideration of the detailed description and accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a block diagram of an ultra-wideband position
tracking system according to one embodiment.
[0009] FIG. 2 is a perspective view of a work vehicle equipped with
the ultra-wideband position tracking system of FIG. 1 according to
one embodiment.
[0010] FIG. 3 is an overhead view of a local area including the
ultra-wideband position tracking system of FIG. 1 according to one
embodiment.
[0011] FIG. 4 is a flowchart of a method of determining a position
of an implement on a work vehicle using the ultra-wideband position
tracking system of FIG. 1 according to one embodiment.
[0012] FIG. 5 is a flowchart of a method of determining a position
of an implement on the work vehicle of FIG. 2 according to one
embodiment.
[0013] FIG. 6 is a flowchart of a method of determining a position
of an implement within the local area of FIG. 3 according to one
embodiment.
DETAILED DESCRIPTION
[0014] Before any embodiments are explained in detail, it is to be
understood that embodiments disclosed herein are not limited to the
details of construction and the arrangement of components set forth
in the following description or illustrated in the following
drawings. Embodiments are capable of other configurations and of
being practiced or of being carried out in various ways.
[0015] A plurality of hardware and software based devices, as well
as a plurality of different structural components may be used to
implement various embodiments. In addition, embodiments may include
hardware, software, and electronic components or modules that, for
purposes of discussion, may be illustrated and described as if the
majority of the components were implemented solely in hardware.
However, one of ordinary skill in the art, based on a reading of
this detailed description, would recognize that, in at least one
embodiment, various aspects may be implemented in software (e.g.,
stored on non-transitory computer-readable medium) executable by
one or more processors. Accordingly, it should be noted that a
plurality of hardware and software based devices, as well as a
plurality of different structural components may be utilized to
implement various embodiments. For example, "control units" and
"controllers" described in the specification can include one or
more electronic processors, one or more memory modules including
non-transitory computer-readable medium, one or more input/output
interfaces, and various connections (e.g., a system bus) connecting
the components.
[0016] FIG. 1 illustrates an ultra-wideband position tracking
system 100 according to one embodiment. In the example illustrated,
the ultra-wideband position tracking system 100 includes an
electronic control unit 105, a first radio frequency (RF) device
110, a second radio frequency (RF) device 115, a global positioning
device 120 (for example, a GPS receiver), and a work vehicle
interface 125. In some embodiments, the ultra-wideband position
tracking system 100 is located on or inside a work vehicle, as
described below. In other embodiments, the ultra-wideband position
tracking system 100 is partially located on or inside the work
vehicle and partially located external to the work vehicle (for
example, located within a work site). Similarly, the electronic
control unit 105 of the ultra-wideband position tracking system 100
may be located in or inside the work vehicle or may be located
externally from the work vehicle (for example, at the work
site).
[0017] In some embodiments, the electronic control unit 105 is
communicatively coupled to both the first RF device 110 and the
second RF device 115. For example, in one embodiment, the
electronic control unit 105 is communicatively connected to both
the first RF device 110 and the second RF device 115 via a
short-range RF connection (for example, local area network,
Bluetooth, and the like). In other embodiments, the first RF device
110 and the second RF device 115 are communicatively connected via
a wired connection. In some embodiments, the electronic control
unit 105 may function as the second RF device 115 by originating
the ultra-wideband RF signals with a single RF transmitter with
multiple antennas (positioned at multiple locations) or multiple RF
transmitters or transceivers positioned at multiple different
locations.
[0018] In addition, in some embodiments, the first RF device 110 is
not communicatively coupled to the electronic control unit 105, but
rather is only communicatively coupled with the second RF device
115. In particular, the second RF device 115 may provide data
communications with the electronic control unit 105, thus
functioning as a master unit with the first RF device functioning
as a slave unit. In this case, the first RF device 110 may be a
secondary or passive device that responds to signals received from
the second RF device 115. In particular, the first RF device 110
may include multiple receivers, repeaters, reflectors, and the like
that are configured to generate a signal only in response to
signals received from the second RF device 115. In some
embodiments, ultra-wideband RF signals generated by the second RF
device 115 are transmitted to the first RF device 110 and trigger
the first RF device 110 to generate an ultra-wideband RF signal for
reception at the second RF device 115. In this way, the first RF
device 110 and the second RF device 115 communicate with each other
via ultra-wideband RF signals while the electronic control unit 105
may communicate via other wireless or wired signals. In particular,
the ultra-wideband RF signals may occupy a bandwidth of greater
than 20% of an arithmetic center frequency or more than 500 MHz. In
some embodiments, the power amplitude of the ultra-wideband ranging
is configured to provide a tracking range that is less than a
length of the work vehicle and the ultra-wideband ranging is
configured such that a decrease in the tracking range results in a
corresponding increase in a tracking accuracy.
[0019] The electronic control unit 105 is also communicatively
connected to the global positioning device 120 and the work vehicle
interface 125. In some embodiments, the global positioning device
120 provides a location of the work vehicle with respect to a
global reference frame. In other embodiments, the global
positioning device 120 provides a location of a work site with
respect to the global reference frame. A site plan may include
references to locations within the global reference frame to
provide information regarding desired terrain or desired
modifications to be performed by the work vehicle at particular
locations within the work site. In particular, the site plan may
outline work to be performed at multiple locations based on the
global coordinates of those multiple locations. The work vehicle
interface 125 may be configured to perform input/output functions
for an operator of the work vehicle. For example, the work vehicle
interface 125 may include a touchscreen display that provides
indications to the operator of the status of the ultra-wideband
position tracking system 100. In particular, the work vehicle
interface 125 may provide indications including audial, visual,
haptic, or a combination of the foregoing regarding positioning of
the work vehicle and positioning of implements on the work
vehicle.
[0020] The electronic control unit 105 includes a plurality of
electrical and electronic components that provide power, operation
control, and protection to the components and modules within the
electronic control unit 105. The electronic control unit 105
includes, among other things, an electronic processor 130 (such as
a programmable electronic microprocessor, microcontroller, or
similar device), a memory 135 (e.g., non-transitory, machine
readable memory), and an input/output interface 140. The electronic
processor 130 is communicatively coupled to the memory 135 and
executes instructions which are capable of being stored on the
memory 135. The electronic processor 130 is configured to retrieve
from memory 135 and execute, among other things, instructions
related to processes and methods described herein. In other
embodiments, the electronic control unit 105 includes additional,
fewer, or different components. For example, the electronic control
unit 105 may be implemented in several independent electronic
control units each configured to perform specific functions or
sub-functions. Additionally, the electronic control unit 105 may
contain sub-modules that generate or transmit control signals to
the first RF device 110 and to the second RF device 115. For
example, the electronic control unit 105 may send a control signal
to the second RF device 115 to initiate transmission of the
ultra-wideband RF signals as discussed herein. In other
embodiments, the electronic control unit 105 may generate and
transmit ultra-wideband RF signals via one or more antennas that
serve as the second RF device 115.
[0021] FIG. 2 illustrates a perspective view of a work vehicle 200
equipped with the ultra-wideband position tracking system 100. In
the example illustrated, the work vehicle 200 includes an implement
205. The implement 205 includes a controllably-movable attachment,
blade, arm, shovel, and the like that is controlled to perform a
work task. For example, the work vehicle 200 may be a road grader
with a blade implement that is controlled to shape a ground
surface. In this example, the implement 205 is moved relative to
the work vehicle 200 to a desired height, angle, inclination, and
the like. In the example illustrated, the work vehicle 200 is
equipped with the first RF device 110 and the second RF device 115.
The first RF device 110 is positioned to move along with the
implement 205. In some embodiments, the first RF device 110 is
fixed to the implement by mounting directly to the implement 205.
The second RF device 115 may be fixed to the work vehicle by
mounting to a fixed position on the work vehicle 200. In addition
to the second RF device 115, multiple additional transceivers 210
may also be positioned at multiple locations on the work vehicle
200 and are operated similar to the second RF device 115 to
determine the position of the first RF device 110 relative to the
work vehicle 200. As shown in the example of FIG. 2, the multiple
additional transceivers 210 are mounted at locations around the
first RF device 110 and on opposite sides of the first RF device
110 to improve the ability of the ultra-wideband position tracking
system 100 to precisely determine the location of the first RF
device 110 (e.g., through triangulation).
[0022] FIG. 3 illustrates an alternative implementation of the
ultra-wideband position tracking system 100 where the second RF
device 115 and the additional transceivers 210 are positioned at
various different locations within a local area (e.g., a job site)
and are not mounted or affixed to the work vehicle 200 itself. The
second RF device 115 and the multiple additional transceivers 210
are mounted at stationary locations relative to the work site. In
the example of FIG. 3, the multiple devices are positioned at
locations on multiple sides of the locations where the work vehicle
200 will be operating (i.e., the work site). In this case, the
multiple devices transmit signals to the first RF device 110
located on the implement 205 of the work vehicle 200. The first RF
device 110 transmits signals back to the second RF device 115 as
the signals are received. This allows the electronic control unit
105 to determine the location of the implement 205 relative to the
second RF device 115, thus determining the location of the
implement relative to the local area. In some embodiments, the
multiple devices may each include a GPS module to define a local
area coordinate system with respect to a global coordinate system
such as GPS coordinates.
[0023] In the example of FIG. 2, a local reference frame is defined
with respect to the work vehicle 200 and the position of the
implement 205 (as defined by the position of the first RF device
110) is determined relative to the work vehicle 200 (in the local
reference frame defined by the placement of the second RF device
115 and any additional transceivers 210). In the example of FIG. 3,
the local reference frame is defined with respect to the job site
and the position of the implement 205 (as defined by the position
of the first RF device 110) is determined relative to the job site
(in the local reference frame defined by the placement of the
second RF device 115 and any additional transceivers 210). In some
implementations of the system illustrated in FIG. 3, the position
of the implement 205 is determined relative to the job site without
reference to the position of the work vehicle 200 itself. In either
case (and as described in further detail below), the position of
the implement 205 is determined relative to the local reference
frame without using GPS and, after determining a position of the
local reference frame relative to a global reference frame (for
example, using GPS), the position of the implement 205 in the
global reference frame can be determined and tracked.
[0024] The first RF device 110 and the second RF device 115 may
implement various techniques for establishing the relative location
of the first RF device 110 with respect to the second RF device
115. The second RF device 115, whether positioned on the work
vehicle 200 or within the local area, generates multiple signals on
multiple sides of the first RF device 110 to establish a positional
determination of the first RF device 110. For example, the
ultra-wideband position tracking system 100 may incorporate time of
flight (i.e. time of arrival) calculations to determine a distance
between the first RF device 110 and the second RF device 115.
Multiple time of flight determinations between multiple RF devices
acting as the second RF device 115 and multiple RF devices acting
as the first RF device 110 may establish a 3-dimensional location
determination within the local area and a determination of the
orientation of the implement 205. In this first example, the
electronic control unit 105, the first RF device 110, and the
second RF device 115 are time synchronized to allow for calculation
of times of flight. In another example, the ultra-wideband position
tracking system 100 may incorporate time difference of arrival
calculations. In this second example, the transmitters are time
synchronized, but not necessarily the first RF device 110 and the
electronic control unit 105. In yet another example, the
ultra-wideband position tracking system 100 may use angle of
arrival calculations. In this third example, the second RF device
115 includes an antenna array that is configured to sense a
reception angle of the transmitted ultra-wideband RF signals. In
yet another example, the ultra-wideband position tracking system
100 may use received signal strength calculations to determine
distance between the first RF device 110 and the second RF device
115. In some embodiments, the ultra-wideband position tracking
system 100 is configured to use a combination of the foregoing
techniques to perform ultra-wideband ranging.
[0025] Although the examples of FIGS. 2 and 3 show only a single RF
device 110 mounted on the implement 205, in some embodiments, the
first RF device 110 includes multiple devices positioned at various
locations on the implement 205. Each of these devices may act
independently in response to signals received from the second RF
device 115. The electronic control unit 105 may determine, based on
the independent responses, the location of each of the multiple
devices using the techniques described above. For example, each of
the multiple devices may be positioned at predetermined positions
on the implement 205, thus establishing a positional relationship
between the multiple devices. Since the relative position of the
multiple devices on the implement 205 is known, the electronic
control unit 105 may determine the precise orientation of the
implement 205. For example, the electronic control unit 105 may
determine the height, angle, depth, and the like of the implement
205.
[0026] FIG. 4 illustrates a method 400 of determining a position of
the implement 205 on the work vehicle 200 using the ultra-wideband
position tracking system 100 according to one embodiment. Prior to
performance of the method 400, the first RF device 110 is
positioned on the implement 205 and the second RF device 115 is
positioned at a fixed location relative to the local reference
frame. In the method 400, the local reference frame is defined by
the electronic control unit 105 (block 405). The local reference
frame provides a mechanism to define a position of the first RF
device 110 locally (i.e., without GPS) as a coordinate system fixed
with respect to the second RF device 115. For example, the local
reference frame may have an origin at the second RF device 115, at
the electronic control unit 105, at a fixed location on the work
vehicle 200, or at a fixed location in the local area. The position
of the first RF device 110 is determined relative to the local
reference frame using ultra-wideband RF ranging (block 410). As
discussed above, the position may be determined using various
ultra-wideband ranging techniques including time-of-arrival, angle
of arrival, time difference of arrival, received signal strength,
or some combination of the foregoing. The position of the implement
205 is then determined relative to the local reference frame based
on the determined position of the first RF device 110 (block 415).
In embodiments that include multiple RF devices as the first RF
device 110, the orientation of the implement 205 is also
determined.
[0027] FIG. 5 illustrates a method of determining the position of
the implement 205 when the second RF device 115 is positioned on
the work vehicle 200 as shown in the example of FIG. 2. Prior to
performance of the method 500, the first RF device 110 is
positioned on the implement 205, and the second RF device 115 is
positioned at a fixed location on the work vehicle 200. In the
method 500, the local reference frame is defined (block 505). The
position of the first RF device 110 relative to the work vehicle
200 is determined by the electronic control unit 105 using
ultra-wideband RF ranging (block 510). The position of the
implement 205 relative to the work vehicle 200 is determined based
on the position of the first RF device 110 (block 515). The
position of the implement 205 relative to a global reference frame
is determined (block 520). This determination may be performed
based on the position of the implement 205 relative to the work
vehicle 200 and the position of the work vehicle 200 relative to
the global reference frame. In particular, the position of the work
vehicle 200 relative to the global reference frame may be
determined based on signals received from the global positioning
device 120.
[0028] In some embodiments, the target position of the implement
205 is also determined (block 525). The target position may be
determined at least in part based on the determined position of the
implement relative to the global reference frame and the site plan
as discussed above. A difference (i.e., a positioning error)
between the target position and the position of the implement 205
relative to the global reference frame is then determined (block
530). The electronic control unit 105 is then able to perform
several functions based on the difference. For example, in one
embodiment, the electronic control unit 105 automatically controls
the position of the implement 205 using control systems in the work
vehicle 200 (block 535). In another example, the electronic control
unit 105 may generate an indication when the difference is greater
than a threshold (block 540). In particular, the electronic control
unit 105 may transmit a signal to the work vehicle interface 125
that generates a notification for the operator of the work vehicle
200. The notification may alert the operator that the implement 205
is out of a predetermined range, which may be adjusted by setting
different values for the threshold. The operator may then manually
reposition the implement 205.
[0029] FIG. 6 illustrates a method of determining the position of
the implement 205 when the second RF device 115 is positioned
within the local area, but is not mounted on the work vehicle 200
itself, as shown in the example of FIG. 3. Prior to performance of
the method 600, the first RF device 110 is positioned on the
implement 205, and the second RF device 115 is positioned at a
fixed location relative to the local area. In the method 600, the
local reference frame is defined (block 605). The position of the
first RF device 110 relative to the local area is determined by the
electronic control unit 105 using ultra-wideband RF ranging (block
610). The position of the implement 205 relative to the local area
is determined based on the position of the first RF device 110
(block 615). The position of the implement 205 relative to a global
reference frame is then determined (block 620). This determination
may be performed based on the position of the implement 205
relative to the local area and the position of the local area
relative to the global reference frame. In particular, the position
of the local area relative to the global reference frame may be
determined based on signals received from the global positioning
device 120.
[0030] In some embodiments, the target position of the implement
205 is also determined (block 625). Similar to the method 500, the
target position may be determined at least in part based on the
determined position of the implement relative to the global
reference frame and the site plan. A difference (i.e., a
positioning error) between the target position and the position of
the implement 205 relative to the global reference frame is then
determined (block 630). The electronic control unit 105 is then
able to perform several functions based on the difference. For
example, in one embodiment, the electronic control unit 105
automatically controls the position of the implement 205 using
control systems in the work vehicle 200 (block 635). This may
include transmitting control information to another electronic
control unit within the work vehicle 200 that is configured to
perform automatic control of the implement 205. In another
embodiment, the electronic control unit 105 may generate an
indication when the difference is greater than a threshold (block
540). In particular, the electronic control unit 105 may transmit a
signal to the work vehicle interface 125 that generates a
notification for the operator of the work vehicle 200. The
notification may alert the operator that the implement 205 is out
of a predetermined range, which may be adjusted by setting
different values for the threshold. As above, the operator may then
manually reposition the implement 205.
[0031] Thus, embodiments provide, among other things, a system and
a method for determining a position of an implement on a work
vehicle using ultra-wideband ranging. Various features and
advantages of the invention are set forth in the following
claims.
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